Merge remote-tracking branch 'kwolf/for-anthony' into staging

* kwolf/for-anthony:
  AHCI: Masking of IRQs actually masks them
  sheepdog: fix co_recv coroutine context
  AHCI: Fix port reset race
  rewrite QEMU_BUILD_BUG_ON
  qcow2: Keep unknown header extension when rewriting header
  qcow2: Update whole header at once
  vpc: Round up image size during fixed image creation
  vpc: Add support for Fixed Disk type
  iSCSI: add configuration variables for iSCSI
  qemu-io: add write -z option for bdrv_co_write_zeroes
  qed: add .bdrv_co_write_zeroes() support
  qed: replace is_write with flags field
  block: perform zero-detection during copy-on-read
  block: add .bdrv_co_write_zeroes() interface
  cutils: extract buffer_is_zero() from qemu-img.c

1 files changed, 7 insertions, 39 deletions

diff --git a/qemu-img.c b/qemu-img.c
index 01cc0d3..c4bcf41 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -515,40 +515,6 @@ static int img_commit(int argc, char **argv)
 }
 
 /*
- * Checks whether the sector is not a zero sector.
- *
- * Attention! The len must be a multiple of 4 * sizeof(long) due to
- * restriction of optimizations in this function.
- */
-static int is_not_zero(const uint8_t *sector, int len)
-{
-    /*
-     * Use long as the biggest available internal data type that fits into the
-     * CPU register and unroll the loop to smooth out the effect of memory
-     * latency.
-     */
-
-    int i;
-    long d0, d1, d2, d3;
-    const long * const data = (const long *) sector;
-
-    len /= sizeof(long);
-
-    for(i = 0; i < len; i += 4) {
-        d0 = data[i + 0];
-        d1 = data[i + 1];
-        d2 = data[i + 2];
-        d3 = data[i + 3];
-
-        if (d0 || d1 || d2 || d3) {
-            return 1;
-        }
-    }
-
-    return 0;
-}
-
-/*
  * Returns true iff the first sector pointed to by 'buf' contains at least
  * a non-NUL byte.
  *
@@ -557,20 +523,22 @@ static int is_not_zero(const uint8_t *sector, int len)
  */
 static int is_allocated_sectors(const uint8_t *buf, int n, int *pnum)
 {
-    int v, i;
+    bool is_zero;
+    int i;
 
     if (n <= 0) {
         *pnum = 0;
         return 0;
     }
-    v = is_not_zero(buf, 512);
+    is_zero = buffer_is_zero(buf, 512);
     for(i = 1; i < n; i++) {
         buf += 512;
-        if (v != is_not_zero(buf, 512))
+        if (is_zero != buffer_is_zero(buf, 512)) {
             break;
+        }
     }
     *pnum = i;
-    return v;
+    return !is_zero;
 }
 
 /*
@@ -955,7 +923,7 @@ static int img_convert(int argc, char **argv)
             if (n < cluster_sectors) {
                 memset(buf + n * 512, 0, cluster_size - n * 512);
             }
-            if (is_not_zero(buf, cluster_size)) {
+            if (!buffer_is_zero(buf, cluster_size)) {
                 ret = bdrv_write_compressed(out_bs, sector_num, buf,
                                             cluster_sectors);
                 if (ret != 0) {